Content Dissemination Systems Including Streaming Systems Lauren Bay, William Barras, Nigel Wallingford CS455: Introduction to Distributed Systems Computer Science Department, Colorado State University

Why is this problem important? Streaming content Netflix Pandora/Spotify Torrents Linux .iso files Software packages Media Publish-Subscribe News

Problem Characterization Content Dissemination Distribution of content over a network Multiple architectures that can be used to distribute content Main Architectures Client-server Peer-to-peer Specific Models Publish-subscribe

Trade-off space for solutions in this area Pros Cons Peer-to-Peer Inexpensive Highly redundant Scalable Client-Server Content replication Data security Ability to regulate traffic Publish-Subscribe Isolated responsibilities Peer-to-Peer Insecure Client-Server No redundancy Publish-Subscribe Transmission problems may go unnoticed

Dominant approaches to the problem (1) Peer-to-Peer More failure resilient Avoids chokepoints Freeloaders can reduce network performance Client-Server Don’t have to rely on other users Can be maintained by one entity

Dominant approaches to the problem (2) Peer-to-Peer DHTs Gossip based networks LiFTing Client-Server Web browsing Netflix

Insights Gleaned Publish-Subscribe Model Helps solve many of the inherent deficiencies of traditional client-server approach Can be paired with client-server or peer-to-peer architecture, ideally for situations where data transmission/reception is time or space decoupled Improving efficiency of existing systems Retrofitting proven systems to make them more suited to modern environments Improving efficiency of low-level protocols IP is an aging technology New protocols, like NDN promise better data routing and enhanced security

What the problem space in the future would look like Migration from client-server to peer-to-peer Content size increasing Online population increasing Changes in content distribution laws Impossible to prevent the illegal distribution of content Disappearance of physical media More convenient and economical to download content than to purchase physical media

Trade-off space and solutions in the future Named Data Networking Replacement for IP Replaces addresses with data names Network routes requests to host with the specified data Very unlikely that everyone will be convinced to switch to a new low level protocol

Questions?